Method and apparatus for connecting a fastener element to a wall

ABSTRACT

A tubular fastener element ( 34 ) is inserted into an opening ( 44 ) in a wall (W) until a flange ( 40 ) at the trailing end of the fastener element ( 34 ) is in contact with the wall (W). Then, an externally threaded end ( 32 ) of a rod ( 28 ) is inserted into a center opening ( 56 ) in the fastener element ( 34 ) from the flange side ( 42 ) of the wall (W) and is mated with internal threads ( 52 ) in the fastener element ( 34 ) beyond the second side ( 50 ) of the wall (W). A tubular mandrel ( 24 ) that surrounds the rod ( 28 ) is moved into contact with the entrance portion of the center opening ( 56 ) in the tubular fastener ( 34 ). The outside diameter of the mandrel ( 24 ) is larger than the inside diameter ( 58 ) of the center opening ( 56 ) in the fastener element ( 34 ). The rod ( 28 ) is retracted to cause a reduced thickness wall portion ( 46 ) of the fastener element ( 34 ) to collapse and form a second radial flange ( 60 ) on the second side ( 50 ) of the wall (W). The mandrel ( 24 ) is forced axially into the center opening ( 56 ) in the fastener element ( 34 ). This causes a tubular end portion ( 36 ) of the fastener element ( 34 ) that is in the opening ( 44 ) in the wall (W) to radially expand into tight engagement with the sidewall of the wall opening ( 44 ). It also cold expands the wall material surrounding the opening ( 44 ) for fatigue enhancement of the wall material.

RELATED APPLICATION

This application is a divisional of U.S. Ser. No. 09/546,359, filed Apr.10, 2000, now U.S. Pat. No. 6,487,767 and entitled Method and Apparatusfor Connecting a Fastener Element to a Wall.

TECHNICAL FIELD

This invention relates to a method and apparatus for connecting aninternally threaded fastener element to a wall by cold expanding anon-threaded tubular portion of the fastener element within an openingin the wall and providing the fastener element with-wall contactingflanges on both sides of the wall.

BACKGROUND OF THE INVENTION

The aerospace industry utilizes a fastener that is in the nature of atubular rivet with internal threads. It can be installed in seconds intoan opening in a wall from one side of the wall. No finishing work isrequired once the fastener is installed. It is ready for use with cleanthreads available for screw attachment. This tubular rivet has a flangeon one end. The opposite end is inserted into the opening in the walland the tubular rivet is pushed into the opening until the flange isagainst the wall. A rod with a threaded end is then inserted into thetubular rivet from the flange side of the wall and is connected tothreads inside the tubular rivet. Then, a hand or power tool is operatedto pull on the rod. This causes a wall portion of the tubular rivet onthe second side of the wall to bulge out radially and form a secondflange that is moved into tight engagement with the second side of thewall. A tubular rivet system of this type is currently provided byRIVNUT® Engineered Products, Inc. of Kendallville, Ind. An early form ofthis type of system is disclosed by U.S. Pat. No. 2,384,347, grantedSep. 4, 1945, to Michael Schultz. A problem with known tubular rivets isthat they often rotate in the opening when torque is applied to a screwthat is connected to the tubular rivet after it has been installed.

It is known to install a nut holder on a wall at the location of anopening in the wall and then connect a nut to the installed nut holder.A tubular stem portion of the nut holder is inserted into the opening inthe wall and is then radially expanded to connect it to the wall andalso cold work the wall material surrounding the opening for fatiguelife enhancement. Then the nut is connected to the nut holder to providebolt receiving threads. Examples of this type of system are disclosed byU.S. Pat. No. 5,096,349, granted Mar. 17, 1992, to Michael A. Landy,Roger T. Bolstad, Charles M. Copple, Darryle Quincey, Eric T.Esterbrook, Leonard F. Reid and Louis A. Champoux, and by U.S. Pat. No.5,468,104, granted Nov. 21, 1995, to Leonard F. Reid and Charles M.Copple. The radial expansion locks the nut holder against rotating butthese systems require attachment of a nut to provide the wall insertwith the internal threads.

There is a need for a method and apparatus for installing a fastenerelement with internal threads in an opening in a wall in such a way thatthe tubular rivet is restrained against rotating in response to a boltbeing threaded into the fastener element. An object of the presentinvention is to provide such a method and apparatus.

BRIEF SUMMARY

According to an aspect of the invention, an internally threaded fastenerelement is inserted into a close fitting circular opening in a wall andis moved axially inwardly until a flange at its trailing end makescontact with the wall where it immediately surrounds the opening. Thefastener element is provided with a tubular end portion that ispositioned inside the opening when the flange is in contact with thewall. The fastener element is also provided with an annular sidewallregion of reduced thickness that is positioned on the second side of thewall axially between the opening in the wall and the internal threads inthe fastener element. A threaded end portion of a rod is inserted intothe fastener element from the first side of the wall and is rotated toconnect it to the internal threads in the fastener element. A tubularmandrel is provided in a surrounding relationship to the rod on thefirst side of the wall. The tubular mandrel has an outer diameter thatis larger than a center opening in the tubular portion of the fastenerelement that is within the opening in the wall. The tubular mandrel alsohas an end portion that is adapted to enter into the center opening fromthe first side of the wall. The rod is retracted axially relatively intoand through the mandrel, to cause the annular sidewall region of reducedthickness to buckle and form a second flange and move the second flangeagainst the second side of the wall, so that the wall is held betweenthe two flanges. Also according to the invention, the mandrel is movedaxially into the center opening of the tubular portion of the fastenerelement that is in the opening. The mandrel is sized so that as it movesinto the center opening it radially expands the tubular portion of thefastener an amount sufficient to firmly connect it to the sidewall ofthe wall opening and hold it against rotation in response to torqueapplied by a screw that this later screwed into the fastener element.

According to a further aspect of the invention, a motor is provided forrotating the rod for threading the threaded end portion of the rod intoand unthreading it out from the internal threads in the fastenerelement.

Another aspect of the invention is to radially expand a tubular memberwithin an opening in a wall, for connecting the member to the wall, bypushing an expansion mandrel axially into a center opening in thetubular portion while holding the tubular portion in the wall. Themember is provided with a flange at its trailing end. The member isinserted into the opening in the wall and pushed forwardly until theflange contacts the wall. The member is held in the opening by insertinga rod through the mandrel, engaging the member with the rod on thesecond side of the opening, and pulling the rod while at the same timecontacting the perimeter of the center opening with the mandrel.

According to another aspect of the invention, a tool is provided forinstalling into a wall opening, a fastener element having a tubularfirst end portion that is sized to fit snugly within the wall opening, acenter opening having an entrance, and an end flange surrounding theentrance. The tool comprises an elongated rod having a longitudinalaxis. The rod is adapted to be rotated about the longitudinal axis. Therod also has an outer end portion that is adapted to be inserted intothe center opening and be connected to the fastener element. The toolincludes a tubular mandrel that projects axially. A center openingextends through the mandrel and the rod extends through the centeropening. The mandrel has an outside diameter that is larger than thecenter opening in the fastener element. The mandrel is movable axiallyback and forth along the rod, towards and away from the outer endportion of the rod.

The tool may also comprise an elongated tubular member within thehousing that is movable back and forth endwise relative to the housing.This tubular member has an outer end and the mandrel is at this outerend. The elongated rod extends endwise from its inner end through theelongated tubular member and the tubular mandrel to its free end.Preferably, there is a piston inside the housing that is connected tothe elongated tubular member and there are a pair of fluid chambers inthe housing, one on each side of the piston. Fluid introduction into andremoval from the fluid chambers cause the back and forth movement of thetubular member.

The tool may also comprise a tubular nose piece that surrounds and isconcentric with the elongated tubular member. The tubular nose piece ismovable endwise back and forth longitudinally along the elongatedtubular member. Preferably also, there is a second piston inside of thehousing that is connected to the tubular nose piece, and there is a pairof fluid chambers in the housing, one on each side of the second piston.Fluid introduction into and removal from the fluid chambers cause theback and forth movement of the tubular member.

These and other advantages, objects, and features will become apparentfrom the following best mode description, the accompanying drawings, andthe claims, which are all incorporated herein as part of the disclosureof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Like reference numerals are used to designate like parts throughout theseveral views of the drawing, wherein:

FIG. 1 is an exploded pictorial view showing the front end portion of apuller tool in a spaced relationship to a fastener element, and showinga threaded rod on the tool that is adapted for engaging the fastenerelement;

FIG. 2 is a view like FIG. 1, but showing the threaded rod entering thefastener element;

FIG. 3 is a view like FIGS. 1 and 2, but showing the threaded rod insidethe fastener element;

FIG. 4 is a fragmentary view showing the front end components of thepuller tool in side elevation and a wall and the fastener element inlongitudinal section;

FIG. 5 is a view like FIG. 4, but showing a mandrel on the tool that ispositioned to where it is ready to move into the fastener element;

FIG. 6 is a view like FIGS. 3 and 5, but showing a relative retractionof the threaded rod for collapsing a wall portion of the fastenerelement so as to form a second wall engaging flange that completes aconnection of the fastener element to the wall;

FIG. 7 is a view like FIGS. 4-6, but showing the mandrel base moved intocontact with the wall and showing the mandrel moved into the portion ofthe fastener element that is in the opening in the wall;

FIG. 8 is a side elevational view of an example puller tool, with someparts shown in section;

FIG. 9 is an enlarged scale longitudinal sectional view of a part of thepuller tool, with same parts shown in side elevation, such view showinga fluid motor schematically;

FIG. 10 is a view like FIG. 9, but omitting some more of the rearportion of the puller tool, such view showing the mandrel base and themandrel extended from the position shown in FIG. 9;

FIG. 11 is a view like FIG. 10, but showing a sleeve that surrounds themandrel base extended from the position shown in FIGS. 9 and 10;

FIG. 12 is an enlarged scale view of the front end portion of the pullertool showing the mandrel and the mandrel base in longitudinal section;

FIG. 13 is a fragmentary view showing the mandrel and portions of themandrel base and showing the threaded rod in side elevation, such viewshowing the mandrel in the same position that is shown in FIG. 6; and

FIG. 14 is a view like FIG. 12, but showing the mandrel in the sameposition that is shown in FIG. 7.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to FIGS. 1-14, a puller tool 10 is shown to comprise anelongated tubular housing 12 having an annular front wall 14. Wall 14includes a center opening 16 through which a tubular sleeve 18 extends.A tubular mandrel base 20 is received within a center opening 22 insleeve 18. A tubular mandrel 24 projects axially outwardly from a radialend surface 26 on mandrel base 20. As best shown in FIG. 12, a rod 28extends through a center opening 30 in the mandrel base 20 and themandrel 24. As will hereinafter be described in greater detail, theinner end of the rod 28 is connected to a rotor 31 within housing 12.The outer or free end of the rod 28 includes a threaded portion 32 thatis adapted to mate with threads that are inside of a fastener element34.

Referring to FIGS. 4 and 5, the fastener element 32 has first and secondopposite end portions 36, 38. End portion 36 is tubular and includes aflange 40 at its outer end. The illustrated flange 40 is adapted to fitinto a tapered countersink 48 that is formed in a wall W on the firstside 42 of the wall W. The countersink 48 is formed at the end of a wallopening 44 on the first side of the wall W. The tubular first endportion of the fastener element 34 includes an annular sidewall region46 of reduced thickness. When the fastener element 34 is positionedwithin the wall opening 44, and the flange 40 is within the countersink48 (FIGS. 13 and 14), the reduced thickness region 46 is positioned onthe second side of the wall W closely adjacent wall surface 50. Fastenerelement 34 includes an internally threaded socket 52, the threads ofwhich mate with the threads on the threaded end portion 32 of the rod 28(FIGS. 4-7). As shown by FIG. 5, the mandrel 24 is movable relativelyalong the rod 28 until its outer end 54 is in contact with the outer endof opening 56 in the tubular first end portion 36 of the fastenerelement 34. FIG. 13 shows that the outer end portion 54 is radiused. Theouter diameter of mandrel 24 is larger than the inner diameter 5B ofcenter opening 56 (FIG. 13). The end portion 54 of mandrel 24 has anouter end that is slightly smaller in diameter than opening 36. As aresult, when the mandrel 24 is moved relatively towards the wall W, theend portion 54 of mandrel 24 is partially within the opening 56.

Referring to FIGS. 5 and 6, when mandrel surface 54 is at the outer endof the opening 56, and the rod 28 is pulled relatively into the mandrel24 and the mandrel base 20, the threaded end portion 32 on rod 28 ismoved towards the mandrel 24. A force is exerted on the fastener element34 that collapses the annular sidewall region of reduced thickness 46,causing it to form a radial second flange 60. The relative pull on therod 28 and the consequent pull on the internally threaded portion 52 ofthe fastener element 34 causes the flange 60 to move tight against thewall surface 50 and at the same time pull the flange 40 tight againstthe countersink surface 48. In a different embodiment, the flange 40 maybe a radial flange having a radial inner surface that is against thesurface 42 of wall W. In such embodiment, the flange 60 is still movedtight against the wall surface 50. Thus, in either embodiment, theportion of the wall W that immediately surrounds the first end portion36 of the fastener element 34 is trapped axially between the conicalflange 48, or a radial flange used in its place, and the flange 60.

In a further embodiment, the flange 40 may be omitted so that the end ofthe end portion 36 of fastener element 34 is flush or over flush whenend portion 36 is within the opening 44. The threaded rod will hold thefastener element 34 in place with the annular outer surface extended tocontact the workpiece and react the pull on the threaded rod 28. The rod28 is pulled into the puller 10, causing the thin wall portion 60 tocollapse against the back of the workpiece W. While still holding thefastener 34 in place by use of the rod 28, the mandrel 24 is pushed intothe opening 56, causing the fastener end portion 36 to be expanded intothe workpiece opening 44. Resistance to torque and push out are achievedby the high interference fit of the expanded fastener in the workpieceopening 44. Elimination of the taper flange eliminates one of thefabrication steps, viz. the countersinking of the workpiece opening 44to receive the flange 40.

Referring to FIGS. 8-14, at its end opposite the rod 28, the rotor 31 isconnected to a shaft 62 that in turn is connected at its end oppositethe rotor 31 to a rotary output of a rotary motor 64, shownschematically in FIG. 9 in the form of a fluid motor. FIG. 9 shows afluid inlet 66 and a fluid outlet 68. The fluid can be compressed airthat is discharged to the atmosphere. Or, it can be hydraulic fluid thatis returned from the motor 64 to either a reservoir or the inlet of apump (not shown) that pumps fluid to the motor 64. Rotor 31 is supportedwithin housing 12 by a suitable antifriction bearing 70. The rod 28 isrotatable relative to the mandrel base 20 and the mandrel 24 but thethreaded end 32 is axially fixed in position.

Referring to FIGS. 8-11, the front end portion includes radial frontwall 14, a radial rear wall 74, and a radial intermediate wall 76. Thereis a sealed connection between the cylindrical wall 12 of the pullertool 10 and the walls 14, 74, 76. Tubular sleeve 18 extends through anopening 16 in wall 14. At its rear end, sleeve 18 includes a piston 80.Piston 80 makes a sealed sliding contact with wall 12. Sleeve 18 makes asealed sliding contact with wall 14. A first working chamber 82 (FIGS. 9and 10) is formed forwardly of piston 80, between piston 80 and wall 14.Chamber 82 is radially between wall 12 and sleeve 18. A chamber 84 isformed on the opposite side of piston 80, axially between piston 80 andwall 76.

The mandrel base 20 is positioned forwardly of a sleeve 86 that extendsrearwardly from mandrel base 20 to a rear end portion 88 that extendsthrough an opening 90 in wall 74. A second piston 92 projects radiallyoutwardly from sleeve 88, at a location axially between walls 74, 76.Sleeve 86 then projects forwardly from piston 92, through an opening 94in wall 76, onto the mandrel base 20 to which its front end is attached.A suitable seal is provided between sleeve 88 and opening 94 and betweenthe outer periphery of the piston 92 and wall 12. A working chamber 96is defined axially between wall 74 and piston 92 and radially betweensleeve 88 and wall 12. On the opposite side of piston 92, a secondworking chamber 98 is formed axially between wall 76 and piston 92, andradially between sleeve 86 and wall 12.

The rotary motor 64 is rotated for the purpose of threading the threadedend portion 32 of rod 28 into or out from the threads 52 in the fastenerelement 34. Initially, the rod 28 and threaded portion 32 are rotated toconnect the threaded portion 32 to a fastener element 34 (FIGS. 1-3).Then, after flange 60 has been formed and the end portion 36 of fastenerelement 34 has been attached to the wall W, the rod 28 and the threadedend portion 32 are rotated in the opposite direction, for unthreadingthe threaded portion 32 from the threads 52.

The puller tool 10 may include a pistol grip handle 100 and thenecessary controls, including a trigger 102, for rotating the motor 64either clockwise or counterclockwise, and for introducing fluid pressureinto one of the working chambers 82, 84 while removing fluid from theother working chambers 82, 84, and for introducing working fluid intoone or the other of the working chambers 96, 98 while removing it formthe other working chamber 96, 98. Or, a coiled return spring could beput into one of the chambers and fluid put into and removed from theother chamber.

As earlier stated, the rod 28 is rotated for the purpose of threadingthe threaded end portion 32 of rod 28 either into or out from theinternal threads 52 is a fastener element 34. The rod 28 only rotates;it does not move axially. However, relative axial movement is caused bymovement of the pistons 80, 92 and the sleeves 18, 86, 88. According toa method of the invention, after a fastener element 34 is attached tothe threaded end portion 32 of the rod 28 (FIG. 3), the tool 10 andfastener element 34 are moved towards the wall W, in alignment with anopening 44 in the wall W, and then the fastener element 34 is moved intoand through the wall opening 44 until its flange 40 is seated on theportion of the wall W that immediately surrounds the wall opening 44.When the flange 40 is a tapered flange, it fits within a taperedcountersink 48. If the flange is a straight radial flange, its innersurface would lie flat on a flat portion of wall 42 which wouldimmediately surround the opening 44. FIG. 4 shows the rod in arelatively extended position and shows the fastener element 34 within anopening 44. Next, fluid is introduced into working chamber 96 and isremoved from working chamber 98. This moves the sleeves 86, 88 and themandrel base 20 and mandrel 24 towards the threaded end portion 32 ofthe rod 28. Initially, movement occurs until the mandrel 24 is in theposition shown by FIG. 5, with its tapered end surface 54 contacting theperimeter of opening 56 in tubular end portion 36. Then, the sleeves 86,88 and the mandrel base 20 and mandrel 24 are moved further towards thethreaded end portion of rod 28. This causes a shortening of the distancebetween the threaded end portion 32 and the mandrel end surface 54. Italso causes a pulling force to be exerted on the second end portion 38of the fastener element 34, pulling it towards the wall W. Mandrel 24exerts a reaction force on the flanged end of fastener element 34,keeping it within the opening 44. The pull on end portion 38 causes theannular sidewall region of reduced thickness 46 to collapse on itselfand move radially outwardly into the position shown by FIGS. 6, 7, 13and 14. The collapsing wall portion 46 forms the flange 60 and is movedinto tight engagement with the second side 50 of wall W. At the sametime, the flange 40 is moved into tight contact with the surface 48 onthe first side 42 of wall W. The portion of the wall W immediatelysurrounding the opening 44 is clamped tightly between the two flanges40, 60. Further movement of the threaded end portion 32 of rod 28towards the mandrel 24, causes the mandrel 24 to be forcibly moved intothe end opening 56 in fastener element 34.

As clearly shown by FIG. 13, the exterior diameter of mandrel 24 isinitially larger than the internal diameter of opening 56. The taperedend surface 54 cams its way into the opening 56, causing the end portion36 of fastener element 34 that is in the opening 44 to be expandedradially. Radial expansion of fastener portion 36 causes a radialexpansion of the wall material immediately surrounding the opening 44.The portion 36 of fastener element 34 is moved into a tight frictionalengagement with the side surface of opening 44 securing the fastenerelement 34 against rotation relative to the wall W. Radial expansion ofthe wall material immediately surrounding the opening 44 may also besufficient to cold expand the wall region for fatigue enhancement. Theexpansion of fitting end portion 36 is sufficient to cause a permanentincrease in the inside and outside diameters of the tubular end portion36. This radial expansion of the tubular end portion 36 does two things.Firstly, it introduced fatigue life enhancing compressive residualstresses in the workpiece W immediately surrounding the workpieceopening 44. Secondly, it creates a high interference fit between thefitting end portion 36 and the sidewall of the opening 44. This highinterference fit secures the fitting 34 to the workpiece W.

For a more complete description of fatigue enhancement by coldexpansion, reference is made to U.S. Pat. No. 3,566,662, granted Mar. 2,1971, to Lewis A. Champoux, entitled “Coldworking Method and Apparatus”.This patent is hereby incorporated herein by this specific reference.

As a comparison of FIGS. 8-13 will show, the annular outer end surface110 on sleeve 18 may be positioned in contact with the wall W as one wayof pulling the threaded end portion 32 of rod 28 relatively into thetool 10 (FIG. 11) Then, the sleeve 18 can be retracted (FIG. 9) in orderto move the threaded end portion 32 relatively outwardly from the tool.Then, an extension of the sleeves 86, 88 may be used to move the mandrel24 and the mandrel base 20 out from sleeve 18 while moving the threadedend portion 32 of rod 28 relatively close to the mandrel 24 and themandrel base 20.

After a fastener element 34 has been attached to the wall W, and themandrel 24 has been moved into the tubular end portion 36 for thepurpose of radially expanding it into the opening 44, the piston 92 inthe sleeves 86, 88 can be retracted for moving the mandrel 24 and themandrel base 20 away from the threaded end portion 32 of rod 28. Afterthe mandrel 24 is completely withdrawn from the end opening 56 in thefastener element 34, the motor 64 can be operated for rotating the rod28 in a direction that unscrews its threads from the threads 52 insideof the fastener element 34. This unthreading is continued until thethreaded end portion 32 is no longer connected to the threads 52. Then,the tool 10 can be easily moved away from the installed fastener element32 in the hole opening 44.

The outer surface of tubular end portion 36 of fitting 34 may bemachined or otherwise treated in order to give it an increasecoefficient of friction. For example, when the fitting is being turnedon a lathe, a series of small grooves may be formed in the outer surfaceof end portion 36, so as to create outwardly projecting rings betweenthe grooves which have sharp edges and will penetrate into the sidewallof the workpiece opening 44 when the end portion 36 is expanded by themandrel 24 as described above.

The illustrated embodiments are only examples of the present inventionand, therefore, are non-limitive. It is to be understood that manychanges in the particular structure, materials and features of theinvention may be made without departing from the spirit and scope of theinvention. Therefore, it is my intention that my patent rights not belimited by the particular embodiments illustrated and described herein,but rather determined by the following claims, interpreted according toaccepted doctrines of claim interpretation, including use of thedoctrine of equivalents and reversal of parts.

What is claimed is:
 1. A tool for installing in a wall opening, afastener element having a tubular first end portion sized to fit snuglywithin the wall opening, an opening having an entrance, and an endflange surrounding the entrance, the tool comprising: an elongated rodhaving a longitudinal axis, the rod being adapted to be rotated aboutthe longitudinal axis, the rod having an outer end portion adapted to beinserted into the opening and be connected to the fastener element; atubular end member having an outer end surface; a tubular mandrelprojecting axially outwardly from the outer end surface, the end memberand mandrel including an opening through which the rod extends, themandrel having an outside diameter that is larger than the opening inthe fastener element; and the end member and mandrel being movableaxially back and forth along the rod, towards and away from the outerend portion of the rod; a tool housing; a rotary motor in the toolhousing coupled to an inner end portion of the elongated rod, theelongated rod and the motor axially fixed with respect to the housing;and a moveable tubular sleeve within the housing, the moveable tubularsleeve mounted for translation back and forth endwise relative to thehousing, the tubular sleeve having one end adjacently located with thetubular end member, and the elongated rod extending endwise from itsconnection with the rotary motor through the tubular sleeve, through thetubular end member, and through the tubular mandrel.
 2. The tool ofclaim 1, further comprising a tubular nose piece surrounding andconcentric with an elongated tubular member, the tubular nose piecebeing movable endwise back and forth longitudinally along the elongatedtubular member, relative to the elongated tubular member, tubular endmember and the tubular mandrel, and the elongated rod.
 3. The tool ofclaim 2, comprising a piston inside the housing connected to the tubularnose piece, and a pair of fluid chambers in the housing, one on eachside of the piston.
 4. The tool of claim 1, comprising a piston insidethe housing connected to the elongated tubular member, and a pair offluid chambers in the housing, one on each side of the piston.
 5. A toolfor securing a fastener into a wall opening, the tool comprising: a toolhousing; an elongated rod having a longitudinal axis, the elongated rodcoupled to the housing for rotation about the longitudinal axis, a firstportion of the rod sized to be received by an opening in the fastenerand detachably engageable with the fastener, a second portion of the rodaxially fixed to the tool housing; a first engagement member having anopening therethrough, the opening sized to receive the rod where thefirst member is longitudinally displaceable with respect to the rod; amandrel having a first end located proximate to the first member and asecond end distally located from the first member, the mandrel furtherhaving an opening sized to receive the rod where the mandrel islongitudinally displaceable with respect to the rod and the toolhousing, the mandrel further having an expanded diameter section and areduced diameter section longitudinally displaced from the expandeddiameter section, the expanded diameter section connected to the reduceddiameter section, a perimeter of the reduced diameter section beingsmaller than a perimeter of the expanded diameter section, and theperimeter of the reduced diameter section sized to be closely receivedinto the opening in the fastener, the expanded diameter section sized tobe forcibly received into the opening of the fastener to a depthsufficient to plastically and radially expand the majority of fastenermaterial located between a near side and a far side of the wall with theopening; and a mechanical actuation device for longitudinally displacingthe mandrel along the rod and for forcibly inserting the mandrel intothe opening of the fastener.
 6. The tool of claim 5 wherein the expandeddiameter section is connected to the reduced diameter section by atapered region.
 7. The tool of claim 5 wherein a first face of the firstmember is in contact with the wall only after a portion of the expandeddiameter section has been projected through the fastener opening to adistance that is approximately equal to the thickness of the wall. 8.The tool of claim 5, further comprising: a bolt head connected to thefastener, the bolt head positioned against and extending from the nearside of the wall.
 9. The tool of claim 8 wherein a first face of thefirst member is in contact with the bolt head only after a portion ofthe expanded diameter section has been projected through the fasteneropening to a distance that is approximately equal to the sum of thethickness of the wall and the thickness of the bolt head.
 10. The toolof claim 5 wherein a first face of the first member is configured toprevent fastener material from being displaced from the opening of thefastener onto the surrounding, near side of the wall.
 11. The tool ofclaim 5, further comprising: a triggering means in communication with alinear actuation means and for initiating the operation of the tool. 12.The tool of claim 5 wherein a force necessary for collapsing thefastener and for forcibly inserting the mandrel into the opening in thefastener is developed internally within the tool.
 13. The tool of claim5 wherein the mechanical actuation device includes at least two chambersand a piston, a position of the piston dependent on fluid pressurewithin the respective chambers, a displacement of the piston coupled toa longitudinal displacement of the mandrel.
 14. The tool of claim 5wherein the mechanical actuation device includes a cam, a rotation ofthe cam calibrated with the longitudinal displacement of the mandrel.15. A tool for cold expanding a fastener into a wall opening, the toolcomprising: a tool housing; an elongated rod having a longitudinal axis,the elongated rod coupled to the housing for rotation about thelongitudinal axis, a first portion of the rod sized to be received by anopening in the fastener and detachably engageable with the fastener, asecond portion of the rod axially fixed to the tool housing; a firstengagement member having an opening therethrough, the opening sized toreceive the rod where the first member is longitudinally displaceablewith respect to the rod; a mandrel having an opening sized to receivethe rod where the mandrel is longitudinally displaceable with respect tothe rod and the tool housing, the mandrel further having a firstposition relative to the first portion of the rod where the rod isdetachably engaged with the fastener; the mandrel having a secondposition relative to the first portion of the rod while at least aportion of the wall of the fastener is collapsed, and the mandrel havinga third position relative to the first portion of the rod where themandrel is inserted into the fastener to a depth sufficient toplastically and radially expand the majority of the fastener materiallocated between a near side and a far side of the wall with the opening;and a mechanical actuation device for moving the mandrel along the rodinto the respective first, second, and third positions.
 16. The tool ofclaim 15 wherein the mechanical actuation device includes at least twochambers and a piston, a position of the piston dependent on fluidpressure within the respective chambers, a displacement of the pistoncoupled to a movement of the mandrel.
 17. The tool of claim 15 whereinthe mechanical actuation device includes a cam, a rotation of the camcalibrated with the movement of the mandrel.